Safety connection and distribution box



Deaa 27 31%Q C. 0 @ALLAHER 294925739 SAFETY CONNECTION AND DISTRIBUTION BOX Original Film Aug. 5, 1943 3 Sheets -Sheet l INVENTOR.

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ATT'YS FDma 27,, 1M9 c. 0. GALLAHER gggjgQ SAFETY coummcuom AND msmzsumom BOX Original Filed Aug. 5, 1943 5 sheets sheet 2 Ba 27;, @949 g, Q, @ALLAHER 2 4? 2 739 SAFETY CONNECTION AND DISTRIBUTION BQX Original Filed Aug. 5, 1943 3 Sheets-Sheet 3 i 'atented Dec. 27, 1949 2,492,739.. SAFETY ooNNEo'rI'oN nisrmsonon 'BOX'; I

Clyde 0, Gallaher, Thomas; W. Va., assignor to The Electric, Railway Equipment C ol npany, Cincinnati, 011m, a corporation of Ohio Original application Aligust 5; 1943,--Serial;N;

497,539. Divided and this application February 18, 1947, Serial No. 729,205

This application is a divisional application of co-p'ending application Serial No. 497,539, new Patent No. 2,424,812. p

The present invention relates to a portable power line extension and power distribution system and has for an object the provision of means whereby such a system is easily and safely established and altered without the use of tools and without the necessity of extending the permanent power lines or permanent feeder lines.

Another object of the invention is to provide a system of insulated cable units and connection; and distribution boxes with a pilot or control arrangement whereby relatively highvol tage is switched on and off at a safe place,- close to the source of current supply for the system, by an automatic and foolproof remote control.

A further object of the invention is to provide connection boxes for the progressive extension of a single set of temporary power lines andadistribution box providing branch .circiii t conned: tions therefrom to the various pieces of electrical apparatus supplied by the system, said boxes being arranged to preclude the possibility of connecting or disconnecting the condiictofs iii the extended system under closed circuit conditions and thereby also avoiding dangerous arcing and the possibility of injury to operators can; the power extension system.

Still another object vof the invention is to .provide in a system of this kind an arrangement of sectional conductors and connectors whereby inproper connections are rendered impossible.

These and other objects are attained by the means herein described and illustrated in the accompanying drawings, in which: a

Fig. 1 is a diagrammatic plan view of an entended power line system of the invent" Fig. 2 is a side elevational view sh ng the positive line compartment of a distribiitioriboir of the invention, in open position, and partly cross section.

Fig. 3 is a fragmental side elevational view showing the negative line compartment of the distribution box in open position, and partly in cross section.

Fig. 4 is a view taken on line 4-4 of Fig. 2', but showing the compartments of the distribution box in closed condition.

Fig. 5 is a top plan view of a connection box of the invention, with the cover open and partly broken away.

Fig. 6 is a cross-sectional view taken on line li of Fig. 5.

p In general the system employs a contactor porary power xtension switch connected toandlocatd adjacent permanent power lines or other power source,,;ffiorri which switch extendsectional cables with inter-'- vening connection bo' 'ies to 's'tablisha s 'gle tein sit a l gul d. a a distribution box conriected to' said 'exte'n i1, and receiving the trailing cable" of a pl alit'y' of electrical machines as branch circuit connections. The entire system is electrically and mechanically iiite'i'loiied' sd'that' it becomes compieteiy' deenergiz'ed whenever any-er connections in the systemarerriered ccessible. v

' The device (if the" invent-ion as illustrated; may be most advantag otisly applied to entry and p11: lar inning operations wherethe operations pre sent problemsof safety which are not involvedelsewhere. In rooin mining operations the cinem -consuming motor driven devices are moved farther away fromt'rie existing power lines as the cutting and ren'ioving operations continue. Where the rooms ver low overhead wirir'ig w'fiu'ldh da gerous to use and costly to ins -l-l. Hertdfof'e', 'ini-ne machines at the viioi-king face were'prpvided individual sets or power cables which brought tl'l'n'rto'the working race of the room. Such pract ce entails dangers due to the miilt-iplicity of cables carrying heavy ai-npe'rags under load in'confinedareas. If any of these be overloaded or broken theymay ignite explosive gases poorly ventilate places. 'Snch practice also handicaps operations which-invoi-ve the suc ce'ssiv use of a number of different electrics-i apparatus. The system of the present invention eiigrrme ts these diffieulties and hazards.

- The jentioilris not tot understood limited to in g operations.- All manner of temporary or portable power line extensions may be safely setup or removed in a minimum of tithe w'i-tho'iit the'u's'e-oitools;

Referring now to Fig.1; [0 representsan exist in'g' positive power line -fromwhich power is tob'e takerifor e'ia pie, into a low room where coal is tobe ent- 1 'd' removed. The negative or -re-' turn line 1-1 may be orin'ectdto the ground rail inn-1e mine, if desired. The lines It and H are herein showndiagrammatically as cor-mooted to aeeneretd? t2 as the sot-rice of power supply.

- By the means-of the present invention a main contactor type switch of snitaiile design, is disposed mesa-y adjacent supply'wires 1-0 and H and is connected to the positive line ['0 "by a con ductor M which} may have a slip connector l5. overload rotection for the entire ystem is pit vided at I as by a fuse" or otner apnrbvd means. The main- --con-tactor switch i3 is always safely located in a properly ventilated part of the mine where explosive gases are not found in dangerous amounts and by confining any heavy arcing to this location and eliminating it at all remote points along the extended power line system the danger of explosions in the rooms is substantially eliminated. A solenoid coil l6, connected to conductor l4, must be included in a closed circuit before it is energized to draw the moving contactor element I 60 into abutment with the spaced apart fixed contacts I] for carrying current beyond the contactor switch to the extension power circuit of the invention. The extension cable sections l8 and I9 employed are single conductor insulated cables which are made up in convenient lengths, e. g., 100 foot lengths, that can be easily extended into the room. The cable sections l8 and I9 each have at opposite ends a slip connector whereby the cables may be electrically connected in end to end relation through the. agency of intermediate members fixedly housed in connection boxes hereinafter described.

The sections l8 and I9 may be identical and interchangeable and each has at its one end a female connector member 20 and at its opposite end a male connector member 2|.

The connection boxes The invention further provides that the several sections of the extended power circuit must be properly connected to fixed connectors disposed in a securely closable connection or distribution box before the circuit is energized. The connection box, indicated generally at 22, comprises a base 23 having a rectangular wall 24 attached thereto. A hingedly connected cover or lid 25 is provided for this box. The wall 24 has slots 26-2'I at opposite ends in the edges thereof which receive the cable sections l8 and IS. The connectors 20 and 2|, are removably seated lengthwise in the connection boxes. The connector members are preferably non-complementary to each other. Projecting from the opposite faces Of a transverse insulating barrier 28 in the connection box 22 are fixed connectors .29 and 30. As can be seen at the top of Fig. 5, the slip connector 20 fits over the fixed male connector 30, while the fixed female connector 29 received the male slip connector 2|, thus electrically connecting two positive cable sections [8. The negative cable sections are connected in a reversed, but otherwise similar fashion.

Mounted on the barrier 28 is a spring opened switch indicated at 3|, and having a plunger 32 that is spring raised when cover 25 is open. but which is automatically closed when said connection box cover 25 is closed and latched. Switch 3| may be of approved explosion-proof type if desired. A pair of oppositely extending fixed male contacts 33 extend into the box from opposite poles of switch 3| (see Fig. Pilot line sections 34 are adapted to carry a positive potential from solenoid it from one connection box 22 to another so long as the switches 3| are closed. The female slip connectors 35 are provided at both ends of each pilot section 34 for removably connecting the positive side of the pilot circuit. The return line for the low amperage pilot circuit is made up of corresponding negative cable sections l9. Removable safet ground connections are provided inside connection boxes 22 and in the distribution box (hereinafter described) in the following manner. U-shaped members 31 are fastened directly t the metal of the connection boxes 22 on opposite sides of the barrier 28 and each of the sections 36 has a strong H-shaped terminal 38 which slides down into the U-shaped member 31 and forms a strong mechanical connection as well as a good safety ground. These connections are relied upon to a considerable extent, in practice, to absorb much of the strain imposed by the occasional necessity of dragging the connected parts of the system over the floor. All cable sections are well insulated and the removable connectors other than 38 are also well insulated on the outside.

Inside the connection boxes are spring raised wire bafiles 39 disposed near and in alignment with the several notches 26 and 21 and conveniently supported on cross rods 48. The bafiles 39 must be individually pressed down from 2. normally vertical position to a substantially horizontal position in order to position the several cable sections in the connection box. If one cable is omitted the baffle 39 at that location remains vertical and it becomes impossible to close the cover 25 of the box and thus close switch 39 without the use of some instrument to turn that baffle down. This serves as a precaution against improperly or incompletely fitting up the connections on the several boxes when the extension system is being assembled on the job. Careless or unskilled labor can be safely used for this job insofar as the safety of the workers and the correctness of the installation is concerned.

Simple complementary latch members 4| and 42 are provided on box 22 and cover 25 to secure the latter and thus hold the switch 3! closed. To preclude the spring baflles 39 from raising the cable section in the notches 26 and 2'! when the cables are properly connected, hinged yoke bars 43 are provided and these have notches to straddle the several cables just behind the slip connectors. Until yoke bars 43 are seated in the manner indicated the cover of the box cannot be closed to complete the pilot circuit. These yoke bars also preclude the slip connectors from pulling away from the complementary fixed connectors after being properly installed.

If desired the simple mechanical spring baffles 39 may be replaced with self-opening switches connected in series and required to be closed and held down by the properly inserted connectors in order to complete the pilot circuit. The mechanical bafiles 39 are preferred from the standpoint of economy and because they render it easier to detect the location of an omitted connection in the system.

The system thus far described affords an easy, rapidl installed and foolproof method and means for extending a single power circuit and a pilot control line as well as a safety ground line which render safe the operation thereof. It will be seen that such a system eliminates the necessity of extending a multiplicity of cables to a number of machines at the working face in a mine.

As will be best understood from Figs. 1, 2, 3 and 4, provision is made for the selective or simultaneos use of one or more electrically driven devtices at the end of the extended power circui The distribution boa:

Distribution box 44 comprises a base plate 45 with two closable compartments, viz: a positive compartment 56 and a negatve compartment 41 mounted thereon in inclined relation to each other and these compartments are provided with hinged covers 48 and 49, respectively (see Fig. 4).

The opposite end walls of compartments 46 and "are provided with notches or slots 56 arranged to receive various cable sections. The covers 48 and 49 close the open tops of slots 50 when the covers are in closed position.

., A pair of pilot switches 5! and 52, which may be of explosionaproof type if desired are mounted in the bottom portions of compartments 46 and "respectively, and are adapted to be independently closed by the closing of covers 48 and 49.- Pilotswitches 5| and 52 are connected in series by a wire 53, one end of one of said switches (52) being connected to the bus bar 54 in the compart: mer t" of distribution box 44, the other side of the other switch (53) being connected with a suitably disposed male connector 33 which is adapted to receive the complementary female connector 35 of a vpilot line section 34. A safety ground conductor 36 provides an electrical bond between the metal of the distribution box and the previous connection box in the extended power system. In essentially the same fashion these safety ground conductors 36 are used be= tween each adjacent pair of connection boxes and between the first of a. series of connection boxes and the negative supply line Hi As will hereinafter be more fully appreciated, the safety ground return line composed of the conductors 36 and the metallic bases of the intervening boxes mustbe fully connected throughout.

In providing for branch utility circuits from the endmost connection box 22 to the distribii tion box 44, a positive cable section l8 has its female connector 20 slidably coupled to a 'iiiale connector 2i which projects from an insulatins barrier 55 in positive compartment 46; A bus bar disposed in the opposite side of the barrier 554s electrically connected with the last men-'- tioned male connector and the bus bar-56 ha'ssuitable number of fuse clips mounted thereon; for example three fuse clips 51, 58 and 59 as shown to accommodate the required fuses =60,-'6l and 62. Another insulating barrier 63 has fuse clips 64, 65 and 6 6 to complete the mounting of fuses 66; 64 and 62 in compartment 465 between the barriers 55 and 63. The several fuses are selected to protect the several current consuming devices which areto receive current from the system. Projecting beyond barrier 63 and connected elee tricaliy with fuse clips 64, 65 and 66 are feniale connectors 200; 261 and 262 of distinctive diifer ent sizes so as to receive the individually oom plementary male connectors 2H], 2H and 212, re= spectively, that are on the free ends of the perma: nent positive trailing cables of the several machines; This method is adopted in order to malte it impossible to connect a machine, a. g.-, an eleo trio drill of low amperage requirement into a socket fused to pass high amperage intended for another machine such as a coal cutting machine. At this point it should be observed that both'the positive and negative trailing cables of all me= chines to be used with the system of the inveri tion are required to be provided with male and fem-ale slip connectors that are polarized pro er female and male connectors which are fixed inthe respective compartments 46 and 416i the'distribution box. v

- As a safety measure, when such further piecautions are demanded, the distribution box is arranged to provide for fuses i'n the negative or return circuits of smaller inachine'st'o preclude a groundedcircuit in any'of the smaller inac mes from taking the full amperage load or *a larger machine; The necessar y'fuses are received in the negative compartment 41 in substantially the same manner as in the positive compartment.

As shown in Fig; l; for example, the motor 61 of an electric drill has a permanently attached positive wire '68; 'the'rr'ee end of which has th male slip connector 212 attached thereto for removable connection with connector 202 in the positive compartment 46 of the distribution box 44. In a like fashion the motor 61 has a permanent negative wire 69 having a female "slip connector 16', for removable connection within negative compartment 41 in circuit with fuse 1|. The drill or any other hand tool circuit is thus doubly fused or protected; Motor 61 is further supplied with an insulated safety gi'oi-ihd cable 12 with one of the connectors 31 on the end removably connectible in a complementary U? shaped member 31 bolted inside compartm nt 41.

The motor '13 of a larger r'riachine, such as a mining maemne (not shown) has its permanent wires,- namely, the positive wife 14, negative 'tiiire 15 and safety grout-id wire 16, rem'ovabl-y can nectible in the distribution box in a Similar mam ner; The positive male connector 211 on the positive wire or trailing table 14 serves to assure connection of the neviee to the properly fused branch circuit; In a like manner aeeaute wire 15 has a slip connector '82 of the female type and safety ground wire 16 has-a connector 38 "thereon;

The motor 11, of another machine; uch as a conveyor has its positive wire 18 permanently attached to male connector 2 11:, while its nega= tive wire 19 has a female connector to and safety ground wire in has a connect-er at thereon. The compartment 41 has an insulating barrier as to which a bus bar 54 is attached, said bar, being provided with the necessary fuse clips for fuses 11 and 1m and a bus 'Wire 1320. Another insulatin barrier 830 has mounted on one face the necessary complementary fuse clips, and on its other" face the several projecting male connectors which are adapted to receive the sup connectors 70, Bl and on the respective trail ing ca-ble's of the machines.

Each of the compartments 46 and 41 has two of the hingedgybke bars 43 with the'proper number: of slots therein to receive the several cable and wire "sections and to preclude any of the properly adjusted sup connectors from being pulled loose. The spring raised yokes or baiiies 39 are mounted on rods 40 in each end of each compartment, in the same manner and for the same purpose, as explained in connection with the connection boxes '22.

L a'tche's 84 and '85 serve to hold the covers of compartments 46 and 41 tightly closed against the switches 5| and 52.

ram the foregoing it will be readily'understood that the distance to which the power extension circuit is carried away from the supply lib-H,- where the contactor switch I3 is located, maybe progressively increased by adding additional con= nection "boxes '22 and the cable sections and by always moving the distribution box 44 to the end of'the system and as near as is reasonable to the location of the work to be'don by the severalcu-rren-t consuming devices supplied b'ythe system It Will be further noted that ii any oablesection it omitted, that fact is 'iil'ade -ilfiinediately apparent by the inability to-clo's'e the box'orboxes iii-which such table should he connected. when all the necessary eebl sections are properly placed meet-vets of all boxes must be securely 7 loted'in order in complete thepi'iot'circiiit which in'turn controls the closing of the main contactor switch l3.

Thus the heavy duty motor 13 is supplied in one fused branch circuit, while another motor 11 is connected in a separate fused branch circuit, and still another motor 6'! is connected in another fused branch circuit. Under this condition the aforementioned connectors must all be inserted in their respective box compartments be fore the lids can be closed. When the lids are properly closed, the pilot switches make contact and a complete pilot circuit through pilot lines is established, and the power circuit is energized. It will be understood that in connecting or dis-' connecting any of the motors it becomes neces-f sary to first open the covers of the distribution box and in opening the first of the two covers, the corresponding. pilot switch is automatically opened and the solenoid coil 16 is deenergized, thus allowing the main contactor switch 13 to automatically open and deenergiz the entire power circuit. If any preceding connection box is opened, deenergization of switch 3 also occurs.

It is impossible for an operator to disconnect from the system any piece of apparatus under his Overload protection for the branch circuits is attained preferably by providing for the use of standard fuses. The connectors are polarized to obviate improper circuits. In practice, I accomplish this polarization by the simple expedient of using different diameters of pin and socket metal in the different mating pairs of connectors. By so doing and by arranging for a fuse of given ampere rating with a given diameter of metal,

the branch cables and the box may be readily designed to the use of any predetermined maximum number of branch outlets, the total of which is predetermined to avoid overloading the extension system or its source of electrical supply.

The boxes and power extension system of the invention are advantageous in many ways both from the standpoint of economy in establishing temporary circuits of any desired length and in the matter of safety. Room mining is usually done under a minimum low ceiling, and the hereinbefore described equipment may be distributed with entire safety against accidental separation of the connectors which are always housed inaccessibly in the connection and distribution boxes so long as any machine is connected in the circuit. The cable sections are all of the heavy insulated and well protected type to afford maximum protection against breakage for these power lines. The pilot cable sections carry verylow amperage and are of lighter weight cable. If the boxes be dragged along the floor, the strain imposed is taken up by the heavier cables. Should pilot circuit 33 be broken by severing the line, only a minimum arc can result, and the entire circuit is forthwith deenergized because solenoid I6 is instantly deenergized.

In the herein described embodiment of the invention the connection boxes and the distribution box are provided with a foolproof safeguard against any possible closing of any pilot switch 8 while the cover of its box is open. The pilot switches 3|, 5| and 52 in the several boxes and compartments are alike so that a description of one will suifice for all.

Reference is made to Fig. 6 wherein the switch 3| is shown mounted within a casing 84 with a slidable cover 85 mounted in opposed grooved flanges 86 on casing 84. Cover 85 has a perforation 8'! (see Fig. 5) which must be in registry with the plunger 32 of the switch in order to depress the said plunger to close the switch. On the inside face of the cover 25 of the box is a lug or finger 88 which passes through the registered perforation 85 to depress the switch plunger only when the box cover is fully closed. A link 89 is pivoted to the inside of box cover 25 at 90 and to the slide cover 85 at 9|. Both ends of the link are desirably upset or burred over on the ends in any well known manner to prevent removal. When the cover 25 is swung open the link pulls slide cover 85 to a position wherein the top of the casing is covered by the imperforate part of slide cover 85. It is thus made impossible to accidentally or otherwise close the pilot switch to endanger persons working on the system. On fully closing of the box cover 25 the link automatically pushes the slide cover to a position wherein the lug 83 may pass through perforation 8? for automatically closing the pilot switch.

The operation of the system has been described in connection with the foregoing disclosure and will be readily understood without further explanation.

What is claimed is:

1. A connection box for a portable power extension system comprising a metallic box structure, a cover hinged thereto, means to latch the cover in closed position, a spring opened pilot switch closable by the cover when said cover is in closed position, a fixed connector on each side of the switch adapted for the reception of pilot line connectors within the box whereby a pilot circuit is completed only upon securely closing the cover, said box having notches at opposite ends for the freely removable reception of insulated cables having connectors, fixed connectors in the box for the removable reception of said cable con nectors, means movably mounted within the box for selectively retaining the cable connectorsagainst removal from the fixed connectors in the box and a plurality of members biased to upright operative position in the box for jointly and sev-" erally precluding closing of said cover, said members being disposed between the respective fixed connectors and the opposed notches in the end wall and adapted to be moved to and held inoperative respectively by the several cables when the slip connectors on the cables are mounted on the fixed connectors.

2. A distribution box for a safety power extension system comprising a base, a pair of metallic compartment structures mounted thereon, independent covers for said compartments, a spring opened pilot switch in each compartment closable by closing of a cover of said compartment, said compartments each having a pair of spaced-apart insulating barriers intermediate opposite ends, a bus bar on one of said barriers, a plurality of fuse clips on said bus bar, a plurality of complementary fuse clips on the remaining barrier opposite said bus bar, a fixed connector electrically connected with the bus bar, independent fixed connectors electrically con-' nected with the fuse clips and a fixed connector electrically connected with one side of the pilot switch in one of the compartments, the pilot switch in the other compartment connected at its one side with the pilot switch in the first mentioned compartment, and at its other side with the bus bar in the said other compartment.

3. A distribution box for a safety power extension system comprising a base, a pair of metallic compartment structures mounted thereon, independent covers for said compartments, a spring opened pilot switch in each compartment closable by closing of a cover of said compartment, slide cover members on the pilot switches actuated by said compartment covers for rendering the switches inaccessible for accidental closing when the respective compartment covers are open, said compartments each having a pair of spaced-apart insulating barriers intermediate opposite ends, a bus bar on one of said barriers, a plurality of fuse clips on said bus bar, a plurality of complementary fuse clips on the remaining barrier opposite said bus bar, a fixed connector electrically connected with the bus bar, independent fixed connectors electrically connected with the fuse clips and a fixed connector electrically connected with one side of the pilot switch in one of the compartments, the pilot switch in the other compartment connected at its one side with the pilot switch in the first mentioned compartment, and at its other side with the bus bar in the said other compartment.

4. In a cover closable box of the class described the combination of a pilot switch! mounted in the box, means on the cover to actuate the switch when the said cover is closed, a housing about said switch including a slide cover having an aperture adapted to register with the switch and pass the switch closing means on box cover, and link means connecting the box cover and slide cover whereby the switch is rendered wholly inaccessible beneath the non-apertured portion of said slide cover.

5. A connector box for a safety portable power extension system comprising side walls and notched end walls, a cover for the box, a transverse barrier in the box, a plurality of fixed connectors extending directly through the barrier opposite certain of the notches in said end walls and adapted at both ends for the reception of removable slip connectors having cables attached thereto with the cables freely and removably seated in the notches in the end walls, a pair of additional fixed connectors extending respectively from opposite faces of the barrier and adapted for reception of slip connectors on additional cables that are removably seated in certain notches in the opposed end walls respectively, a hinged member in each end of the box adapted to be raised for permitting mounting and removal of all of the slip connectors on and from the fixed connectors and adapted in raised position to preclude closing of the cover, independent members biased to upright position intermediate each fixed connector and an opposed notch in the adjacent end wall for jointly and severally precluding closing of the cover, said members individually rendered inoperative by a cable seated in the adjacent notch in the end wall, and a spring opened pilot switch closable by the cover and electrically connected in series with the said pair of additional fixed contacts. CLYDE O. GALLAHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 459,523 Keller et a1 Sept. 15, 1891 1,017,110 Rogers Feb. 13, 1912 1,402,297 Kellner Jan. 3, 1922 1,453,696 Ball et al May 1, 1923' 1,992,392 Rah et al Feb. 26, 1935 2,280,334 Workman Apr. 21, 1942 2,317,667 Chandler Apr. 27, 1943 2,339,496 Madeira Jan. 18, 1944 2,422,755 Strother June 24, 1947 2,439,708 Abraham Apr. 13, 1948 FOREIGN PATENTS Number Country Date 817,924 France June 7, 1937 

